-- ==
-- input { [[[1,2,3],[4,5,6],[7,8,9]],[[10,20,30],[40,50,60],[70,80,90]]] }
-- output { [[[1,2,3],[4,5,6],[7,8,9]],[[10,20,30],[40,1337,60],[70,80,90]]] }
def main [n] [m] [o] (xss: *[n][m][o]i32) =
  scatter_3d xss [(1, 1, 1), (1, -1, 1)] [1337, 0]
